SCIENCE OF COMMON THINGS. 7< 



Velocity of winda. Force of winds. 



Because in their passage they absorb very little water, 

 as they do not blow over large oceans. 



479 Why do our "hands and lips chap in frosty and windy weather 1 



Because a cold, dry wind absorbs moisture from the 

 surface of the skin ; and this action, in turn, causes the 

 skin to crack and inflame. 



480 Would the wind blow regularly from east to west if all obstructions 

 were removed ? 



Without doubt. If the whole earth were covered 

 with water, the winds would always follow the sun, 

 and blow uniformly in one direction. 



481 Do winds ever blow regularly f 



Yes, in those parts of the world which present a 

 large surface of water, as in the Atlantic and Pacific 

 Oceans. 



483 With what velocity do winds move f 



Every graduation exists in the speed of winds, from 

 the mildest zephyr to the most violent hurricane. 



483 With what velocity does a wind which is hardly perceptible move f 



With a velocity of about one mile per hour, and 

 with a perpendicular force on one square foot of *005 

 Ibs. avoirdupois. 



484 In a gentle wind, what is the velocity and estimated pressure f 



'From four to Jive miles per hour, and a force of "079 

 to 123 Ibs.* 



485 In a very brisk wind, what is the velocity and pressure ? 



From twenty to twenty -free miles per hour / force 1*9 

 to 3-07 Ibs. 



4SQ What is the velocity and pressure of the wind in a storm t 



From fifty to sixty miles per hour, with a pressure 

 of 7 to 12 Ibs. 



487 In a hurricane, what is the estimated velocity and pressure f 



From eighty to one hundred miles per hour> with a 

 varying force of 31 to 50 Ibs. 



* In these estimates the pressure is computed per square foot in 

 pounds avoirdupois. 



